metadump: Define metadump v2 ondisk format structures and macros

The corresponding metadump file's disk layout is as shown below,

     |------------------------------|
     | struct xfs_metadump_header   |
     |------------------------------|
     | struct xfs_meta_extent 0     |
     | Extent 0's data              |
     | struct xfs_meta_extent 1     |
     | Extent 1's data              |
     | ...                          |
     | struct xfs_meta_extent (n-1) |
     | Extent (n-1)'s data          |
     |------------------------------|

The "struct xfs_metadump_header" is followed by alternating series of "struct
xfs_meta_extent" and the extent itself.

Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

diff --git a/include/xfs_metadump.h b/include/xfs_metadump.h
index a4dca25cb9cd6fcdc2414099587866446ee34acd..e9c3dcb8f711b91e20191a574d42c8907a21af99 100644 (file)
--- a/include/xfs_metadump.h
+++ b/include/xfs_metadump.h
@@ -8,7 +8,9 @@
 #define _XFS_METADUMP_H_
 
 #define        XFS_MD_MAGIC_V1         0x5846534d      /* 'XFSM' */
+#define        XFS_MD_MAGIC_V2         0x584D4432      /* 'XMD2' */
 
+/* Metadump v1 */
 typedef struct xfs_metablock {
        __be32          mb_magic;
        __be16          mb_count;
@@ -23,4 +25,70 @@ typedef struct xfs_metablock {
 #define XFS_METADUMP_FULLBLOCKS        (1 << 2)
 #define XFS_METADUMP_DIRTYLOG  (1 << 3)
 
+/*
+ * Metadump v2
+ *
+ * The following diagram depicts the ondisk layout of the metadump v2 format.
+ *
+ * |------------------------------|
+ * | struct xfs_metadump_header   |
+ * |------------------------------|
+ * | struct xfs_meta_extent 0     |
+ * | Extent 0's data              |
+ * | struct xfs_meta_extent 1     |
+ * | Extent 1's data              |
+ * | ...                          |
+ * | struct xfs_meta_extent (n-1) |
+ * | Extent (n-1)'s data          |
+ * |------------------------------|
+ *
+ * The "struct xfs_metadump_header" is followed by alternating series of "struct
+ * xfs_meta_extent" and the extent itself.
+ */
+struct xfs_metadump_header {
+       __be32          xmh_magic;
+       __be32          xmh_version;
+       __be32          xmh_compat_flags;
+       __be32          xmh_incompat_flags;
+       __be64          xmh_reserved;
+} __packed;
+
+/*
+ * User-supplied directory entry and extended attribute names have been
+ * obscured, and extended attribute values are zeroed to protect privacy.
+ */
+#define XFS_MD2_COMPAT_OBFUSCATED      (1 << 0)
+
+/* Full blocks have been dumped. */
+#define XFS_MD2_COMPAT_FULLBLOCKS      (1 << 1)
+
+/* Log was dirty. */
+#define XFS_MD2_COMPAT_DIRTYLOG                (1 << 2)
+
+/* Dump contains external log contents. */
+#define XFS_MD2_COMPAT_EXTERNALLOG     (1 << 3)
+
+struct xfs_meta_extent {
+       /*
+        * Lowest 54 bits are used to store 512 byte addresses.
+        * Next 2 bits is used for indicating the device.
+        * 00 - Data device
+        * 01 - External log
+        */
+       __be64 xme_addr;
+       /* In units of 512 byte blocks */
+       __be32 xme_len;
+} __packed;
+
+#define XME_ADDR_DEVICE_SHIFT  54
+
+#define XME_ADDR_DADDR_MASK    ((1ULL << XME_ADDR_DEVICE_SHIFT) - 1)
+
+/* Extent was copied from the data device */
+#define XME_ADDR_DATA_DEVICE   (0ULL << XME_ADDR_DEVICE_SHIFT)
+/* Extent was copied from the log device */
+#define XME_ADDR_LOG_DEVICE    (1ULL << XME_ADDR_DEVICE_SHIFT)
+
+#define XME_ADDR_DEVICE_MASK   (3ULL << XME_ADDR_DEVICE_SHIFT)
+
 #endif /* _XFS_METADUMP_H_ */